Personal computer systems in general and IBM personal computers in particular have attained widespread use for providing computer power to many segments of today's modern society. Personal computer systems can usually be defined as a desktop, floor standing, or portable microcomputer that consists of a system unit having a single system processor, a display monitor, a keyboard, one or more diskette drives, a fixed disk storage, and an optional printer. One of the distinguishing characteristics of these systems is the use of a motherboard or system planar to electrically connect these components together. These systems are designed primarily to give independent computing power to a single user and are inexpensively priced for purchase by individuals or small businesses.
Examples of such personal computer systems are IBM's PERSONAL COMPUTER AT, IBM's PERSONAL SYSTEM/2 Models 25, 30, 35, 40 SX, 55 SX, 57 SX, 70, 80, 90 and 95, and IBM PERSONAL SYSTEM/1 computers. These systems can be classified into two general families. The first family, usually referred to as Family I Models, use a bus architecture exemplified by the IBM PERSONAL COMPUTER AT and other "IBM compatible" machines. The second family, referred to as Family II Models, use IBM's MICRO CHANNEL bus architecture exemplified by IBM's PERSONAL SYSTEM/2 Models 55 SX through 95. Beginning with the earliest personal computer system of the Family I models, such as the IBM Personal Computer, it was recognized that the operating system would be of utmost importance. Realizing that market acceptance was a primary goal, IBM chose a rather simple text oriented operating system which was suited for the level of hardware technology of the time. The operating system chosen was named DOS which is the acronym for disk operating system. The limited objectives for DOS at the time were non-cryptic commands, English language error messages (instead of error codes, small memory size (12 Kbyte) and reasonable performance. DOS served well for the Family I machines and even into the basic Family II models, but as memory and hardware prices declined and performance increased a more user friendly intuitive operating system was needed. Beginning in 1986, IBM started development of a graphical user interface (GUI) designed to mask the complexity of the hardware technology advances and present to the user an intuitive, flexible, and easy-to-use system. This operating system was named OS/2 and was developed for the more advanced technology of the Family II models.
Additionally, other manufactures have investigated and used other types of GUI systems. One of the earliest in the personal computing area was Xerox's STAR system that presented the user with icons representing a particular operation or software application. Later, APPLE's Macintosh system added features such as windows and drag and drop to further the intuitive nature of the graphical user interface for APPLE's line of computers. Presently, MICROSOFT's WINDOWS provides a graphical user interface on IBM compatible machines.
With GUI systems, the computer system is controlled using a pointing device such as a mouse. The pointing device controls the location of a pointer that appears on the screen of the computer's display device. Elements on the screen such as icons, which are graphical representations of various modules such as disk drives, applications and documents, or windows, which are rectangular areas on the screen in which applications or documents can be viewed, may be manipulated using the mouse. In this way, the underlying devices which the elements represent may be controlled.
As GUI systems developed, producing the underlying elements such as windows and icons has become well known. In fact, publicly available tools such as icon and window editors are now available to actually create the visual display. For example, Conklin, OS/2 Notebook, (Microsoft Press, 1990) pp. 159-255 discusses OS/2 software tools.
As new models of the personal computer family were introduced, OS/2 had to be updated and enhanced. One of the major features of the OS/2 Version 2.0 operating system in which the present invention is incorporated is a workplace shell featuring a desktop metaphor. Briefly, the desktop metaphor presents the user with the look of a desktop. For example, files can appear as icons grouped together into folders. Folders can be placed into a predefined space such as a window. Application programs appear as unique icons that can be activated when a pointer, positioned by the movement of a mouse over the icon, is energized usually by double clicking one of the mouse buttons.
Prior GUI systems such as IBM OS/2 Version 1.3 and Microsoft Windows provide three states of windows, namely, the maximized, minimized and the restored states. The minimized state realizes the window as an icon. The maximized state results in the window being displayed at the largest supported size of a particular computer display or at the size of the available display area. For example, FIG. 1 shows a window 2 in the maximized state. As seen in FIG. 1, the maximized window 2 occupies substantially the entire viewing area of display screen 4.
The restored state refers to any size of the window other than the maximized and minimized states. For example, FIG. 2 depicts window 2 in a restored state wherein window 2 occupies less than the entire display screen 4.
Unfortunately, in such prior systems, when a window was in the maximized state, the only way to make a size adjustment to the maximized window was to change the window from the maximized state to the restored state. Once the window was in the restored state, the size could be adjusted by clicking on the border of the window and moving the border via mouse action to adjust the size and dimensions of the window. The requirement of entering the restored state before making any sizing adjustments to a maximized window undesirably consumes the user's valuable time which is a precious commodity in the modern computing environment.